J/A+A/694/A143 TOI-5108 and TOI 5786 radial velocities (Thomas+, 2025)
TOI-5108 b and TOI 5786 b: Two transiting sub-Saturns detected and characterized
with TESS, MaHPS and SOPHIE.
Thomas L., Hebrard G., Kellermann H., Korth J., Heidari N., Forveille T.,
Sousa S.G., Schoeller L., Riffeser A., Goessl C., Serrano Bell J.,
Kiefer F., Hara N., Grupp F., Ehrhardt J., Murgas F., Collins K.A.,
Bieryla A., Parviainen H., Belinski A.A., Esparza-Borges E., Ciardi D.R.,
Clark C.A., Fukui A., Gilbert E.A., Hopp U., Ikuta K., Jenkins J.M.,
Latham D.W., Narita N., Nielsen L.D., Quinn S.N., Palle E., Pippert J.-N.,
Polanski A.S., Ries C., Schmidt M., Schwarz R.P., Seager S., Strakhov I.A.,
Striegel S., van Eyken J.C., Watanabe N., Watkins C.N., Winn J.N.,
Ziegler C., Zoeller R.
<Astron. Astrophys. 694, A143 (2025)>
=2025A&A...694A.143T 2025A&A...694A.143T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Optical
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: detection - stars: planetary systems -
planets and satellites: gaseous planets
Abstract:
We report the discovery and characterization of two sub-Saturns from
the Transiting Exoplanet Survey Satellite (TESS) using high-resolution
spectroscopic observations from the MaHPS spectrograph at the
Wendelstein Observatory and the SOPHIE spectrograph at the
Haute-Provence Observatory. Combining photometry from TESS, KeplerCam,
LCOGT, and MuSCAT2 with the radial velocity measurements from MaHPS
and SOPHIE we measure precise radii and masses for both planets.
TOI-5108 b is a sub-Saturn with a radius of 6.6±0.1R⊕ and a
mass of 32±5M⊕ TOI-5786 b is similar to Saturn with a radius
of 8.63±0.12R⊕ and a mass of 72±8M⊕. Both planets
are close to their host stars with periods of 6.75 days and 12.78 days
respectively. This puts TOI-5108 b just inside the bounds of the
Neptune desert while TOI-5786 b is right above the upper edge. We
estimate hydrogen-helium envelope mass fractions of 38% for TOI-5108 b
and 74% for TOI-5786 b. However, using a model for the interior
structure that includes tidal effects the envelope fraction of
TOI-5108 b could be much lower (∼20$) depending on the obliquity. We
estimate mass-loss rates between 1.0x109g/s and 9.8x109g/s for
TOI-5108 b and between 3.6x108g/s and 3.5x109g/s for TOI-5786 b.
Given their masses, this means that both planets are stable against
photoevaporation. Furthermore, at these mass-loss rates, there is
likely no detectable signal in the metastable helium triplet with the
James Webb Space Telescope. We also detect a transit signal for a
second planet candidate around TOI-5786 with a period of 6.998 days
and a radius of 3.90±0.16R⊕ Using our RV data and
photodynamical modeling, we are able to provide a 3-σ upper
limit of 26.5M⊕ for the mass of the potential inner companion
to TOI-5786 b.
Description:
The following files include the radial velocity observations with the
MaHPS and SOPHIE spectrographs that were used to confirm and measure
the masses of the planets around TOI-5108 and TOI-5786.
Objects:
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RA (2000) DE Designation(s)
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11 05 04.60 +11 14 47.7 TOI-5108 = TIC 350348197
19 33 17.35 +30 42 15.2 TOI-5786 = TIC 40292751
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
toi5108.dat 69 148 TOI-5108 RV data (table 8)
toi5786.dat 69 88 TOI-5786 RV data (table 9)
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See also:
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
Byte-by-byte Description of file: toi5108.dat toi5786.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d Time Time of observation in BJD
20- 42 F23.16 m/s RV Radial velocity (relative for MAHPS observations)
44- 62 F19.16 m/s e_RV Error of the radial velocity
64- 69 A6 --- Inst Instrument used for the observation
(MAHPS or SOPHIE)
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Acknowledgements:
Luis Thomas, lthomas(at)usm.lmu.de
(End) Patricia Vannier [CDS] 09-Jan-2025